Chroniosaurus is an extinct genus of chroniosuchid stegocephalian, often considered a reptiliomorph[1] but possibly a stem-tetrapod,[2] from upper Permian (upper Tatarian age) deposits of Novgorod, Orenburg and Vologda Regions, Russia.

[3] It was first named by Tverdokhlebova in 1972 and the type species is Chroniosaurus dongusensis.

[3] Its lifestyle is uncertain.

An early study suggested a fairly aquatic lifestyle,[4] but its femoral microanatomy[5] and dorsal dermal plates[6] suggest a rather terrestrial lifestyle.

This article about a prehistoric tetrapod is a stub.